Differential Response of Cafeteria roenbergensis to Different Bacterial and Archaeal Prey Characteristics

Daniele De Corte, Gabriela Paredes, Taichi Yokokawa, Eva Sintes, Gerhard J Herndl

In the marine environment, the abundance of Bacteria and Archaea is either controlled bottom-up via nutrient availability or top-down via grazing. Heterotrophic nanoflagellates (HNF) are mainly responsible for prokaryotic grazing losses besides viral lysis. However, the grazing specificity of HNF on specific bacterial and archaeal taxa is under debate. Bacteria and Archaea might have different nutritive values and surface properties affecting the growth rates of HNF. In this study, we offered different bacterial and archaeal strains with different morphologic and physiologic characteristics to Cafeteria roenbergensis, one of the most abundant and ubiquitous species of HNF in the ocean. Two Nitrosopumilus maritimus-related strains isolated from the northern Adriatic Sea (Nitrosopumilus adriaticus, Nitrosopumilus piranensis), two Nitrosococcus strains, and two fast growing marine Bacteria (Pseudoalteromonas sp. and Marinobacter sp.) were fed to Cafeteria cultures. Cafeteria roenbergensis exhibited high growth rates when feeding on Pseudoalteromonas sp., Marinobacter sp., and Nitrosopumilus adriaticus, while the addition of the other strains resulted in minimal growth. Taken together, our data suggest that the differences in growth of Cafeteria roenbergensis associated to grazing on different thaumarchaeal and bacterial strains are likely due to the subtle metabolic, cell size, and physiological differences between different bacterial and thaumarchaeal taxa. Moreover, Nitrosopumilus adriaticus experienced a similar grazing pressure by Cafeteria roenbergensis as compared to the other strains, suggesting that other HNF may also prey on Archaea which might have important consequences on the global biogeochemical cycles.

Department of Limnology and Bio-Oceanography
Microbial Ecology: an international journal
Publication date
Publication status
E-pub ahead of print
Peer reviewed
Austrian Fields of Science 2012
106021 Marine biology
bacterivory, grazing
ASJC Scopus subject areas
Agricultural and Biological Sciences(all)
Portal url